git-annex/Utility/Parallel.hs

{- parallel processes
 -
 - Copyright 2012 Joey Hess <joey@kitenet.net>
 -
 - Licensed under the GNU GPL version 3 or higher.
 -}

module Utility.Parallel where

import Common

{- Runs an action in parallel with a set of values.
 - Returns values that caused the action to fail. -}
inParallel :: (v -> IO ()) -> [v] -> IO [v]
inParallel a l = do
	pids <- mapM (forkProcess . a) l
	statuses <- mapM (getProcessStatus True False) pids
	return $ map fst $ filter (failed . snd) $ zip l statuses
	where
		failed v = v /= Just (Exited ExitSuccess)
the syncer now pushes out changes to remotes, in parallel Note that, since this always pushes branch synced/master to the remote, it assumes that master has already gotten all the commits that are on the remote merged in. Otherwise, fast-forward prevention may prevent the push. That's probably ok, because the next stage is to automatically detect incoming pushes and merge. 2012-06-22 19:46:21 +00:00			`{- parallel processes`
			`-`
			`- Copyright 2012 Joey Hess <joey@kitenet.net>`
			`-`
			`- Licensed under the GNU GPL version 3 or higher.`
			`-}`

			`module Utility.Parallel where`

			`import Common`

			`{- Runs an action in parallel with a set of values.`
			`- Returns values that caused the action to fail. -}`
			`inParallel :: (v -> IO ()) -> [v] -> IO [v]`
golfing 2012-06-23 05:33:10 +00:00			`inParallel a l = do`
			`pids <- mapM (forkProcess . a) l`
the syncer now pushes out changes to remotes, in parallel Note that, since this always pushes branch synced/master to the remote, it assumes that master has already gotten all the commits that are on the remote merged in. Otherwise, fast-forward prevention may prevent the push. That's probably ok, because the next stage is to automatically detect incoming pushes and merge. 2012-06-22 19:46:21 +00:00			`statuses <- mapM (getProcessStatus True False) pids`
golfing 2012-06-23 05:33:10 +00:00			`return $ map fst $ filter (failed . snd) $ zip l statuses`
the syncer now pushes out changes to remotes, in parallel Note that, since this always pushes branch synced/master to the remote, it assumes that master has already gotten all the commits that are on the remote merged in. Otherwise, fast-forward prevention may prevent the push. That's probably ok, because the next stage is to automatically detect incoming pushes and merge. 2012-06-22 19:46:21 +00:00			`where`
golfing 2012-06-23 05:33:10 +00:00			`failed v = v /= Just (Exited ExitSuccess)`